There is an alternator for vehicle provided with a front bracket and a rear bracket that support a front bearing and a rear bearing rotatably supporting a rotor, which is a rotating body, in a rotatable manner and configured in such a manner that components immovably supported on the rear bracket on an opposite side to the rotor are covered with a cover made of an insulator, such as resin. It is required to form the cover in such a manner that the cover is configured to expose the alternator terminal B (where it is connected to the battery mounted on a vehicle) and also the terminal insertion opening of the connector (where it is connected to the vehicle connector), and thereby making no problems when in use. At the same time, the cover configuration to protect other electrical components from the external environment is required.
For example, Patent Document 1 describes such a cover shaped like bottomed cylindrical and attached to the alternator main body with at three screw fixing portions and one hook-like fixing portion.